Hi,

For your application, I would recommend using the Statistical API. There is an excellent webinar here that can introduce to its features.

The best example for you to work from can be found in the default Statistical API example in the Request Builder application. This calculates NDVI for Sentinel-2 and can be easily adapted to calculate NDWI for your purposes.

This will return a .json, which can then be read and written into a pandas dataframe using Python, this in turn can be exported as a .csv file. If you aren’t familiar with these libraries I can find some example code blocks that you can use.